China: Heavy-Duty Truck and Bus Engines
Implementation dates for the emission standards for heavy-duty vehicles are listed in Table 1.
|Type Approval||All Vehicles|
a Public buses and municipal service vehicles|
b All vehicles
c Starting 2016.01, DPFs are also required on new public HDDVs (buses and municipal service vehicles)
d Beijing, Shanghai, Tianjin, Hebei, Liaoning, Jiangsu, Zhejiang, Fujian, Shandong and Guangzhou
e Public transportation buses, sanitary and postal vehicles
China III-VI Standards
With a few exceptions, emission standards for new heavy-duty truck and bus engines are based on the European standards. The legislation for China III-V stages—which are based on Euro III-V, respectively—was adopted in 2005 . The emission limits are shown in Table 2. Proposed limits for Beijing VI are also included .
|China III||ESC + ELR||2.1||0.66||-||5.0||0.10a||0.8|
|China IV||ESC + ELR||1.5||0.46||-||3.5||0.02||0.5|
|China V||ESC + ELR||1.5||0.46||-||2.0||0.02||10d||0.5|
|Beijing VIb CI||WHSC||1.5||0.13||0.40||0.010||8.0×1011||10|
|Beijing VIb PI||WHSC||1.5||0.13||0.41||0.40||8.0×1011|
* Applicable only to gas engines|
a 0.13/0.21 (ESC/ETC) for engines < 0.75 L per cylinder and rated speed > 3000 rpm
b Proposed Beijing VI limits 
c Some heavy-duty vehicles can be chassis certified instead of engine certified 
d Cycle average; 25 ppm maximum
|At the China I/II stage (not shown in the table), the test was ECE R-49 or the Chinese 9-mode.|
The following provisions apply to emissions of nitrogen dioxide and ammonia:
- NO2 requirements: OEMs are required to report tailpipe NO2 concentration and NO2 increase level if an oxidation catalyst-based aftertreatment system is used, such as DOC, POC, DPF or NAC.
- NH3 slip limit: No limit for China IV. For China V and later, as shown in Table 2.
Supplemental China IV and V Requirements
Supplemental requirements have been adopted to prevent excess NOx emissions during low-speed, urban driving conditions from some heavy-duty diesel vehicles (HDDVs) type approved to Euro IV and V equivalent standards. These requirements include:
- World Harmonized Transient Cycle (WHTC) limits—applicable in Beijing and nationally, and
- PEMS testing requirements—applicable in Beijing.
The Beijing Municipal Environmental Protection Bureau (EPB) released two local standards in February 2013 and the Ministry of Environmental Protection adopted a national standard in January 2014. These standards are supplemental to China IV and V standards and apply to China IV and V vehicles with Gross Vehicle Weight above 3,500 kg, registered in Beijing and nationally, respectively.
WHTC Limits. One of the Beijing standards  implemented March 1, 2013 and the national standard  implemented January 1, 2015, require China IV and V engines to be tested over the WHTC in addition to the ETC (in Europe, testing over the WHTC is not required until the Euro VI stage). The Beijing standards apply to diesel and gas fueled engines while the national standards apply to only diesel fueled engines. Both cold-start and hot-start tests are required, with results weighted 14% and 86%, respectively. Table 3 and Table 4 provide the WHTC cycle limits for the China IV and V stages. Most of the limit values are equal to the Euro IV/V ETC values except those for NOx emissions.
|China IV||2013.03||4.0||0.55||1.1||3.7 (3.5)c||0.03|
|China V||2013.07d||4.0||0.55||1.1||2.8 (2.0)c||0.03|
a Only gas engines
b Not applicable to gas engines
c ETC cycle limits shown in parentheses
d Buses and sanitary vehicles; other vehicles upon availability of suitable fuel in the regions surrounding Beijing
|China IV||2015.01||4.0||0.55||4.7 (3.5)a||0.03|
|China V||in line with China V||4.0||0.55||2.8 (2.0)a||0.03|
|a ETC cycle limits shown in parentheses|
PEMS Testing. The second Beijing standard , implemented July 1, 2013, establishes in-use, complete vehicle Portable Emission Measurement System (PEMS) testing requirements for manufacturers to prove that real-world emissions do not overly exceed the type approval limit values. There are two options that manufacturers can choose from to calculate emissions values from PEMS testing: the work-based window method and the not-to-exceed (NTE) method.
Emission durability requirements, including the engine useful life and the minimum aftertreatment testing periods, are shown in Table 5. The aftertreatment periods according to HJ 438-2008 are mandatory for type approval and production conformity, while GB 20890-2007 provides a guideline to conduct aftertreatment durability testing during product development.
|Category||Useful Life||Aftertreatment Testing|
|Ch I-V||Ch VI||GB 20890-2007||HJ 438-2008|
|M1 (GVW > 3.5 t)|
|100,000 km/5 yrs||50,000 km||100,000 km|
|M3 (GVW ≤ 7.5 t)|
N2 and N3 (GVW ≤ 16 t)
|200,000 km/6 yrs||300,000 km/6 yrs||60,000 km||125,000 km|
|M3 (GVW > 7.5 t)|
N3 (GVW > 16 t)
|500,000 km/7 yrs||700,000 km/7 yrs||80,000 km||167,000 km|
The GB 20890-2007 standard recommends that aftertreatment testing be conducted on-vehicle, over the China Heavy-Duty Durability Cycle—Vehicle (C-HDD-V). Alternatively, an engine based durability test can be conducted over the China Heavy-Duty Durability Cycle—Engine (C-HDD-E).